The training of academic medical oncologists with expertise in basic, translational, clinical and health services research remains an important priority for academic medical centers throughout the United States. This task has become increasingly critical as the discipline of medical oncology translates basic science principles into clinical practice. The UCLA Hematology/Oncology clinical fellowship program aims at offering high quality comprehensive clinical and research training for medical oncologists. The program has excelled in the training of academic medical oncologists in the past 30 years, having generated several of the success stories in medical oncology and trained investigators that have reached the highest levels in academic ranks in several institutions. The Hematology/Oncology fellowship training program includes an initial year of full time clinical training with inpatient and outpatient rotations to fulfill the subspeciality board requirements for certification eligibility in Medical Oncology. Salary support for this initial clinical period is derived from Divisional and University funds. From the pool of Hematology/Oncology fellows we select 2-3 fellows per year to be included in the 24 month "Academic Training in Medical Oncology" (abbreviated as Oncology T32), for which we request funding in this proposal. This is a second revised application. In this submission we have made major changes in the training program that arise from the prior review cycles: The Director has been changed from Dennis Slamon, M.D., Ph.D., to Antoni Ribas, M.D., Ph.D. The main reason is to refocus the program to foster the training of physician-scientists in oncology research. The training faculty has been markedly changed. We have used new selection criteria for the training faculty (mainly peer reviewed funding, independent research programs and experience as mentors), which has resulted a marked decrease in the proposed faculty (from 55 to 29), of whom half are newly appointed training faculty. The Oncology T32 is re-organized into 3 training tracks, basic, translational and clinical research, with different faculty and curriculum for each track and defined criteria for the determination of success of trainees and mentors. The fellowship program has had recent success in attracting underrepresented minority (URM) trainees. Newly proposed plans to increase URM in the program include a proactive approach in the selection of URM and the addition of mentors with a track record of training URM.